Energy:
Potential Energy is the energy of position and potential energy vaires with the amount of Kinetic Energy.
    • Potential Energy is expressed as Mass x Gravity x height (MGH)

Gravitational Potential Energy:
Gravitational Potential Energy = weight x height
Kinetic Energy is the energy of motion and is inversly proportional to Potential Energy.
    • Kinetic Energy is expressed as (1/2) mass x velocity squared ((1/2)mv^2)
    • If the speed of an object is doubled, the kinetic energy of the object is quadrupled.
      • it takes 4x as much work to double the kinetic energy.
Both Kinetic and Potential Energy are measured in Joules (J)
Mechanical Energy:
is using both potential energy and kinetic energy and decides the true energy that an object exerts.
Work: When work is described as "How long?" meaning a variation of time the equation reads as Force x Time (W=FT) This is called Impulse
When work is described a as being "How long?" in a variation of distance the equation reads as Force x Distence (W=Fd)
Basically work is the movement of something over time and distance.
2000N of force going a distance of 4 meters the equation is 2000(4)= 8000J
Power: Doing work does not describe a human because if a human is running he gets tired and therefore is not running at a constant pace, so we use Power to determine work and distance. Power is described as Force x distance/ Time Interval (Fd/T) or more simply Work done / Time Interval (W/T).
Power is measured in Watts (W).
So if there is 500J of work done over a 5 second time there is 100W of Power.

Law of Conservation of Energy:
Energy cannot be created or destroyed. It can be transformed from one form to another, but the total amount of energy never changes.

Machine: a device used to multiply forces or simply to change the direction of forces.
  • Lever - the work done at one end is equal to the work done on the load at the other end.
  • Fulcrum - pivot point of the lever
  • Pulley - a type of lever that can be used to change the direction of a force
Mechanical Advantage: The ratio of output force to input force for a machine
Efficiency = Useful work output or actual mechanical advantage
Total work input theoretical mechanical advantage
  • efficiency will always be a fraction less than 1
    • example .45 x 100% or 45% efficiency
    • a 4 engine airplane gives out .25 efficiency so total it gives out 100% efficiency (25% per engine)
Energy for Life: all life needs some sort or energy whether it be a human needing food and carbs for energy or plants needing sunlight (photosynthesis) so they can survive.